An extension of the nature of the oxidation products of 2,3-dihydro-5-hydroxytryptamine is planned. The principle methodology will be analysis and structural assignments using gas chromatographic mass spectrometry of the oxidation products. An attempt to employ this "reduced serotonin" as a specific cytotoxic agent to manipulate serotonin containing vessles, will be furthered. The nature of the inhibition of DOPA decarboxylase by hydrazine type inhibitors will be pursued. The structure of the condensation product formed with pyridoxal-5-phosphate will be defined. The effect of the inhibitors in the kinetic properties of the adrenal vs. kidney enzyme activity will be examined. BIBLIOGRAPHIC REFERENCES: Fellman, J.H., Roth, E.S., Fujita, T.S. Decarboxylation to tyramine is not a major route of tyrosine metabolism in mammals. Arch. of Biochem. and Biophys. 174, 562-567, 1976. Fellman, J.H., Roth, E.S., Heriza, E.L., Fujita, T.S. Altered Pattern of Dopa Metabolism. Biochem. Pharm. 25, 222-223, 1975.